Efficacy of botulinum toxin type A in myogenic temporomandibulardisorders: a single arm, prospective, pilot study

Background: Myogenous temporomandibular disorders (TMDs) is commonly associated with myofascial pain and functional limitations. Botulinum toxin type A (BoNT-A) has shown potential in relieving chronic muscular pain. Methods: In this single arm, prospective, pilot study, 25 patients diagnosed with myofascial TMDs received a single bilateral intramuscular injection of 50 units of BoNT-A. Assessments using the Visual Analog Scale (VAS), Chronic Pain Index (CPI), Jaw Functional Limitation Scale (JFLS-8), and Oral Health Impact Profile (OHIP-14) were performed at baseline, 6 weeks, and 12 weeks post-treatment. Results: Significant reductions in pain (VAS: 6.84 ± 1.03 to 0.84 ± 0.94) and CPI (61.87 ± 8.12 to 9.86 ± 4.46) were observed. Functional improvement (JFLS-8: 5.82 ± 0.56 to 1.08 ± 0.51) and enhanced quality of life (OHIP-14: 24.56 ± 8.39 to 5.96 ± 2.79) were also significant. No adverse effects were reported. Conclusions: BoNT-A showed promising results in reducing pain and improving function in patients with myofascial pain in Temporomandibular Disorders (M-TMDs). However, the single-arm design, small sample size, and short follow-up limit causal inference and external validity. These findings should be interpreted as preliminary. Clinical Trial Registration: Clinicaltrials.gov, identifier NCT05651256.